/*
 * Copyright (c) 2005, 2011, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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/*
 * $Id: PGPData.java,v 1.4 2005/05/10 16:35:35 mullan Exp $
 */
package javax.xml.crypto.dsig.keyinfo;

import java.util.Collections;
import java.util.List;
import javax.xml.crypto.XMLStructure;

/**
 * A representation of the XML <code>PGPData</code> element as defined in
 * the <a href="http://www.w3.org/TR/xmldsig-core/">
 * W3C Recommendation for XML-Signature Syntax and Processing</a>. A
 * <code>PGPData</code> object is used to convey information related to
 * PGP public key pairs and signatures on such keys. The XML Schema Definition
 * is defined as:
 *
 * <pre>
 *    &lt;element name="PGPData" type="ds:PGPDataType"/&gt;
 *    &lt;complexType name="PGPDataType"&gt;
 *      &lt;choice&gt;
 *        &lt;sequence&gt;
 *          &lt;element name="PGPKeyID" type="base64Binary"/&gt;
 *          &lt;element name="PGPKeyPacket" type="base64Binary" minOccurs="0"/&gt;
 *          &lt;any namespace="##other" processContents="lax" minOccurs="0"
 *           maxOccurs="unbounded"/&gt;
 *        &lt;/sequence&gt;
 *        &lt;sequence&gt;
 *          &lt;element name="PGPKeyPacket" type="base64Binary"/&gt;
 *          &lt;any namespace="##other" processContents="lax" minOccurs="0"
 *           maxOccurs="unbounded"/&gt;
 *        &lt;/sequence&gt;
 *      &lt;/choice&gt;
 *    &lt;/complexType&gt;
 * </pre>
 *
 * A <code>PGPData</code> instance may be created by invoking one of the
 * {@link KeyInfoFactory#newPGPData newPGPData} methods of the {@link
 * KeyInfoFactory} class, and passing it
 * <code>byte</code> arrays representing the contents of the PGP public key
 * identifier and/or PGP key material packet, and an optional list of
 * elements from an external namespace.
 *
 * @author Sean Mullan
 * @author JSR 105 Expert Group
 * @see KeyInfoFactory#newPGPData(byte[])
 * @see KeyInfoFactory#newPGPData(byte[], byte[], List)
 * @see KeyInfoFactory#newPGPData(byte[], List)
 * @since 1.6
 */
public interface PGPData extends XMLStructure {

  /**
   * URI identifying the PGPData KeyInfo type:
   * http://www.w3.org/2000/09/xmldsig#PGPData. This can be specified as the
   * value of the <code>type</code> parameter of the {@link RetrievalMethod}
   * class to describe a remote <code>PGPData</code> structure.
   */
  final static String TYPE = "http://www.w3.org/2000/09/xmldsig#PGPData";

  /**
   * Returns the PGP public key identifier of this <code>PGPData</code> as
   * defined in <a href="http://www.ietf.org/rfc/rfc2440.txt">RFC 2440</a>,
   * section 11.2.
   *
   * @return the PGP public key identifier (may be <code>null</code> if not specified). Each
   * invocation of this method returns a new clone to protect against subsequent modification.
   */
  byte[] getKeyId();

  /**
   * Returns the PGP key material packet of this <code>PGPData</code> as
   * defined in <a href="http://www.ietf.org/rfc/rfc2440.txt">RFC 2440</a>,
   * section 5.5.
   *
   * @return the PGP key material packet (may be <code>null</code> if not specified). Each
   * invocation of this method returns a new clone to protect against subsequent modification.
   */
  byte[] getKeyPacket();

  /**
   * Returns an {@link Collections#unmodifiableList unmodifiable list}
   * of {@link XMLStructure}s representing elements from an external
   * namespace.
   *
   * @return an unmodifiable list of <code>XMLStructure</code>s (may be empty, but never
   * <code>null</code>)
   */
  @SuppressWarnings("rawtypes")
  List getExternalElements();
}
